What is the simplest way of joining WinMx on the basis I will only want to upload or download music ?
join a music centric channel and right click various users names... select 'browse' from the menu... look for a file you want... select it by left click and click download...
search is often broken but can be used as well during the random few times it works... (this will have to be trial and error on your part since none of us can 'predict' for you when its working or not)
stay in the room you are in... others will be browsing around as well.. this will give you the upload opportunity...
Can these "attacks" on WinMX users play havoc with my PC ?
yes... as such i recommend connecting as a 'secondary' ... its in the tab that says networks and is usually selected by default apon installation of winmx...